Ceramics are becoming the materials of choice for dental restorations because of their superior esthetics, their biocompatibility, chemical durability and wear resistance. Their appeal is enhanced by concern over the use of metals in the mouth, in particular dental amalgam, and the demand for esthetics from patients. The structural properties and clinical performance of this class of brittle material are strongly influenced by surface and subsurface defects produced by machining and other fabrication procedures. In the clinical context, defects from machining operations, and from contact fatigue and wear, can lead to premature clinical failures. The proper route to understanding how such defects initiate and propagate to cause such failures is a fundamental study of underlying deformation and microfracture properties, which are in turn governed by the intrinsic material microstructure. Accordingly, microstructural characterization becomes a critical element in the specification and design of dental ceramics. The problem calls for a strong dialogue between dental researchers and materials scientists. The overall objective of this proposal is to enhance clinical performance of current and future dental ceramic restorative materials by establishing fundamental relationships between intrinsic microstructural characteristics and machining parameters, maximizing surface integrity and minimizing fatigue and wear. The investigations will be performed under a central Program Plan Organization. Four synergistic associated projects are proposed which focus on machining (Project 1), fracture and fatigue (Project 2), wear (Project 3), and surface enhancement for machinability and performance (Project 4). A statistical Core is proposed to work with each of the projects. A Technology Integration Core is proposed to establish a formalized mechanism to integrate findings from all of the projects. An Administrative and Technology Transfer Core will oversee Program-Project activities to ensure that investigations are completed in a timely fashion, within budget as well as to expedite transfer of information internally between team members as well as externally to dentists, engineers and material scientists. A unique team has been assembled from academia, research laboratories, and industry. A number of innovative cost sharing factors have added significant value to the Program-Project. The intellectual and physical resources are exceptional. The multidisciplinary approach proposed can determine the critical knowledge base relating the fundamental interactions between material microstructure and machining parameters in special relation to surface integrity, fatigue, and wear for dental restorative materials. It provides a means to ensure the evolution of the next generation of high performance ceramics for dental restorations.